1. Field of the Invention
This invention relates to a sensor malfunction detection system for a gas-turbine engine, more specifically a sensor malfunction detection system for a gas-turbine aeroengine used in aircraft.
2. Description of the Related Art
Gas-turbine engine control is performed by using the outputs of a group of sensors installed in the engine to discriminate the engine operating condition and conducting various kinds of control, including calculation and control of the amount of fuel to be supplied, based on the discriminated condition. If a sensor should fail because of wire breakage or the like, its output will deviate from the right value. This makes it necessary to detect whether any of the sensors are faulty.
Japanese Laid-open Patent Application No. Sho 61(1986)-241424 teaches a technique for selecting the best value among two sampled values of a sensor output and composite signals representing nominal values with respect to parameters thereof.
Japanese Laid-open Patent Application No. Hei 6(1994)-050174 teaches a technique that determines or checks whether sensor output is within an a permissible range, responds to each determination that it is not within the permissible range by resetting the upper and lower limits of the permissible range in accordance with the direction of the deviation, counts the number of times that the inputted value in the next cycle swings up and down within the permissible range within a predetermined time period, and determines that the sensor is faulty when the count value exceeds a predetermined value.
The conventional technique of 61-241424 requires creation of composite signals representing nominal values with respect to parameters corresponding to the sensor output and selection of the best value from among these and two sampled values of the sensor output, while the conventional technique of 6-050174 requires resetting of the upper and lower limits of the permissible range in accordance with the received sensor output. Thus, both techniques are complicated.